Pulse Modulated Laser Sight for Firearms

ABSTRACT

A laser sighting device for a semi-automatic handgun having a recoil spring guide chamber housing a recoil spring surrounding a spring guide. The laser sighting device includes a pulse modulated laser received within the spring guide, having an input and a light output for emitting a pulse modulated laser light aligned with a path of a bullet fired by the handgun; and a sensor for detecting firing of the handgun, having an output coupled to the input of the pulse modulated laser. When the sensor detects the handgun has been fired, the output of the sensor triggers the pulse modulated laser to emit a train of pulses of laser light.

REFERENCE TO RELATED APPLICATIONS

This application claims one or more inventions which were disclosed in Provisional Application No. 61/322,407, filed Apr. 9, 2010, entitled “PULSE MODULATED LASER SIGHT FOR FIREARMS”. The benefit under 35 USC §119(e) of the United States provisional application is hereby claimed, and the aforementioned application is hereby incorporated herein by reference.

FIELD OF THE INVENTION

The invention pertains to the field of laser sights for firearms. More particularly, the invention pertains to a modulated laser pulse to indicate the trajectory of a real or simulated firearm projectile.

BACKGROUND OF THE INVENTION

Various devices have been developed to aid in the field of firearm training, such as those for use by law enforcement and military personnel. Lasers mounted to the training firearm have become popular devices. However, they are most often associated with awkward devices mounted externally on the firearm to emit a laser pulse upon “firing”. These have their drawbacks, as explained below.

For example, U.S. Pat. No. 3,633,285 (Sesney) describes a laser emitting device for training purposes. This device is separately mounted to the firearm, usually on top of the barrel, thus being capable of being used with any firearm. The laser is triggered when an acoustical detection device receives a distinctive sound resulting from activation of the firing mechanism. The laser beam is detected by a number of light detectors to show the path of the imaginary bullet. This device may also be used in conjunction with blank cartridges and live rounds, as well.

U.S. Pat. No. 3,938,262 (Dye et al.) describes a laser aiming device for use with rifles. The laser device uses a piezoelectric crystal, the entire device being mounted on a rifle barrel. Upon the firing of blank rounds, the resulting shock wave stimulates the piezoelectric crystal to send out a laser pulse. In addition, the piezoelectric component responds to the mechanical shockwave generated by the motion of the hammer or firing pin to trigger the emission of a laser light pulse.

U.S. Pat. No. 4,934,086 (Houde-Walter) discloses a laser device that is mounted within the recoil spring guide chamber of a semi-automatic handgun, such as the design exemplified by the well known Model 1911 Colt. The laser and its circuitry are mounted to the handgun, thus eliminating the potential for loss of adjustment that is common with externally mounted lasing devices. The laser light beam is cycled on and off by a switch mounted at a convenient location on the handgun. It emits a single beam that remains on before, during and after firing of the weapon until manually turned off by the shooter. The power source for this device is located in the grip, or optionally, may be designed into a magazine so that a fresh power source is provided with each magazine. U.S. Pat. No. 5,509,226 is an improvement on the '086 device in that the entire laser mechanism is contained within the spring guide chamber. In addition to providing a long life battery, the laser is “flashed” in order to prolong the life of the battery.

U.S. Pat. No. 5,605,461 (Seeton) discloses a firearm training device much like Dye et al., in that a piezoelectric crystal is programmed to respond to the falling of the hammer on the firing pin (or the activation of the firing pin by a spring-like device). This higher amplitude sound wave stimulates the laser light emitting device, such as a laser diode, to emit a laser pulse, the duration of which may be adjusted to determine if the trainee is “pulling” the weapon upon firing, which can result in missing the target or at least not hitting the “center mass” of the targeted object. This device is mounted on the outside of the firearm and a light detecting device receives and tracks the laser output.

Recent developments in laser sight technology include “dual mode” devices. Such devices emit a laser light for sighting purposes, and concurrently for tracking the trajectory of a projectile. Mode one is an operational mode that maintains a constant laser light to assist the shooter in aiming the firearm. Mode two is a target practice mode, which upon sensing certain functions that ultimately result in the firing of weapon, emits a laser light that is parallel to the trajectory of the bullet and identifies the point of impingement of the trajectory on a sensory target board. The second mode is intended to be used with an electronically sensitive target, so that even blanks can be employed rather than live rounds.

U.S. Pat. No. 5,344,320 (Inbar et al.) describes a dual mode laser sighting mechanism for firearms. The mechanism is mounted onto the barrel of a rifle. A manual switch is used to change from the constant light aiming mode to the firing responsive intermittent target mode. U.S. Pat. No. 6,572,375 (Schechter et al.) discloses another dual mode laser training system for use with blank cartridges. The device is mounted at any one of a number of locations on the exterior of the firearm. Sensors are provided to detect mechanical shock waves. Such sensors include accelerometers, acoustic detectors and piezoelectric crystals.

SUMMARY OF THE INVENTION

The firearm laser sighting device of an embodiment of the present invention is mounted in the recoil spring guide chamber of a semi-automatic handgun. The laser emits a constant light that allows the shooter to aim at a specific target. The laser light is then modulated to emit a pulsed light at or about the time of firing the weapon. The emission of the modulated laser light can be adjusted to pulse the laser light for any duration of time, from a few microseconds to a couple of seconds. The activation of the modulated laser light can be triggered by any number of conventional means. Such means include an acoustical sensor, a mechanical shockwave sensor to detect the movement of either the hammer or the movement of the bullet moving down the barrel, or a light sensor, to detect the flash of light at the moment the bullet leaves the end of the barrel. The laser pulse can be modulated by a stream of data from a ROM chip and programmed to emit a pulsed light code to be detected by a MILES (“multiple integrated laser engagement system”) targeting system or a variety of conventional training systems.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a partial cut-away of the side of a semi-automatic handgun showing an embodiment of the pulse modulated laser device.

FIG. 2 shows an exploded view of the various components of an embodiment of the pulse modulated laser device mounted within the spring guide.

FIG. 3 shows a side elevation partial cross sectional view of the assembled pulse modulated laser device inside a partially sectioned view of the recoil spring guide chamber.

FIGS. 4A & 4B shows an automatic pistol, with the slide in firing position and in recoiled position, respectively.

FIG. 5 shows a graph of a programmed modulated dual mode laser pulse sequence of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a semi-automatic handgun 10 having an external slide ejection element 11. Non-limiting examples of such semi-automatic handguns include those manufactured by Colt (the most common of which is the Model 1911 and its progeny), Browning, Sig Sauer, Beretta, Glock, Heckler & Koch, and Smith & Wesson.

Such automatic and semi-automatic handguns use a recoil compression spring to absorb the energy from the rearward motion of an external slide ejection element. The stored energy is available to eject a spent cartridge from the handgun after the bullet has been fired and to enable another live round to be chambered from the magazine into the receiver of the barrel. The spring 12 and spring guide 14 are located in a recoil spring guide chamber 13 which is positioned under and parallel with the barrel 16. The recoil spring guide chamber 13 is a cavity which is closed at a first end 15 and open at the opposing or second end 17. The spring guide 14 is hollow and accommodates the installation of a pulse modulated mode laser 100.

A laser light 18 is generated by a laser diode 20 and is projected through a collimating lens 22 located in a lens holder or housing as shown in FIG. 2. The laser light 18 may be emitted at any frequency, including visible, ultraviolet and both near and far infra-red wavelengths.

Referring to FIGS. 1 and 2, at one end of the lens housing 21 is a window 25 through which a laser light 18 is emitted. At least one set screw 23 adjusts the lens holder 21, thereby aligning the laser light 18 with the axis of the barrel 16. Coupled with the laser diode 20 is a driver board 27 that controls the function of the laser light 18. The lens holder 21 and the driver board 27 are installed within a hollow cylindrical casing 29. The casing 29 is surrounded axially by recoil spring 12. The laser diode 20 is in electrical contact with battery 30 via spring 31.

The battery 30 may be either rechargeable or non-rechargeable. Various types of batteries that may be used to power the pulse modulated dual mode laser include, but are not limited to, alkaline, lithium, nickel cadmium, nickel-metal hydroxide, carbon zinc, polymer lithium ion, and silver oxide. Multiple batteries may be stacked in series and are herein collectively referred to in the singular. The battery 30 is retained within the casing 29 by posterior cap 42. Between the posterior cap 42 and the battery 30 is a spring and contact pin 66.

The recoil spring 12 and casing 29 are located within recoil spring guide chamber 13 as shown in FIG. 3. The window 25 of the lens housing 21 is contained within a concentric hole in an anterior cap 45, which is located at the second end 17 of the recoil spring guide chamber 13 in proximity to the muzzle of barrel 16. The posterior cap 42 of casing 29 is seated against the first end 15 of the recoil spring guide chamber 13.

An alignment notch 60 may be added to or integrally formed as part of the outer surface of the posterior cap 42. The alignment notch 60 sits within a corresponding receiver seat within the recoil spring guide chamber 13 to insure that the path of the laser light 18 corresponds to the path of a real or simulated trajectory from the barrel 16. Fine tuning the path of the laser light 18 may be made by manipulating the at least one adjusting screw 23.

The driver board 27 includes at least one sensor 50 which activates the emission of a pulse modulated laser light. The sensor 50 is preferably a type of acoustical sensor and can detect the powder flash as the bullet leaves the muzzle of the barrel 16. Alternatively, the sensor could be a piezoelectric vibration sensor, a MEMS (micro electro mechanical system) accelerometer, a Hall Effect magnetic sensor, a Reed Effect magnetic sensor, a capacitive sensor, a microphone, or an optical sensor. Or, the sensor could be a mechanical switch, such that laser activation can occur by the recoil motion of the slide ejection element 11 movement which temporally causes an electrical disconnect of the battery 30 and the contact pin 65 of the posterior cap 42, which instructs the laser to fire a pulse (this type of switch is shown in U.S. Pat. No. 5,509,226, the contents of which are hereby incorporated herein by reference).

FIGS. 4A and 4B show a semi-automatic fire arm having a sensor 50—for example, a Hall Effect magnetic sensor or a Reed Effect magnetic sensor—with the slide 11 in pre-firing or “battery” position in FIG. 4A, and with the slide 11 retracted in FIG. 4B as the firearm is discharged.

In the battery position (ready to be fired) as shown in FIG. 4A, the slide ejection element 11 is in its fully forward location. A magnet 38 is installed within or onto the slide ejection element 11 at a predetermined location forward of the position of the sensor 50. The magnetic field projected by the magnet 38 is represented by vector M.

Referring to FIG. 4B, as the firearm is discharged, the recoil force from the firing of the round causes the slide ejection element 11 to retract rearward, as represented by vector R. At some point in the rearward movement of the slide ejection element 11, the magnetic field M triggers the Hall or Reed Effect sensor 50 to generate a signal to cause the laser diode 20 to emit a pulse modulated laser light.

The laser pulse can be modulated, for example by a stream of data from a ROM chip programmed to emit an encoded stimulated pulse. A separate pulse code can be assigned to different shooters in order to track the marksmanship of each shooter. The encoded stimulated pulse can to be detected by a MILES (“multiple integrated laser engagement system”) targeting system or a variety of other laser detection systems.

A switch can be mounted on the gun and has an output coupled to an input of the pulse modulated laser to turn the laser on and off. Some examples are shown in FIG. 1. Various switches include a manually operated grip switch 28, trigger switch 26, side mounted lever switch 35 or a conductive metal slide lock switch 65 (FIG. 2 and as discussed hereinabove with respect to U.S. Pat. No. 5,509,226). Also, a motion sensitive mercury or MEMS switch may be used to turn on the laser in response to the motion of the shooter drawing the firearm from a holster.

FIG. 5 shows a graph of intensity 101 of the light 18 emitted by the laser 20 during a shooting session. When the laser is turned on at T₀, a test pulse 102 can be provided to verify proper operation of the modulation. The light intensity increases to an increased level L₂ for the duration of the test pulse 102, then declines to a constant level L₁, in which the laser light 18 can be used as a sighting aid. Alternatively, it will be understood that if the use of a sighting aid is not required, the lower level L₁ could be “off”, with little or no light emitted between pulses, and the test level L₂ could also be the same as the bright level L₃. The test pulse 102 could be omitted entirely if desired.

At time T₂, the gun is fired and the intensity is modulated between L₁ and a bright level L₃ for a pulse train 103 comprising a series of pulses 104. After the chosen pulse duration, at T₃, the laser returns to the constant level L₁.

The duration of the train 103 of pulses 104 of the modulated laser light can be adjusted for any duration of time. Further, a different pulse “train” can be developed for each shooter. Different pulse “trains” can be programmed to include a different number of individual pulses, or a pattern of long-and-short pulses can be generated as a binary code, as is known to the art of pulse modulated optical signals. Each individual pulse can vary from approximately 10 nanoseconds to approximately 100 nanoseconds in duration. Each pulse “train” can consist of any number of a plurality of individual pulses and can vary in total duration from approximately 100 nanoseconds to approximately 200 microseconds.

The pulse modulated mode laser 100 may be either a single diode or a dual diode laser. A dual diode laser contains two diodes, one for use as a sighting designator and the other one responding to a stimulus to generate a pulse modulated laser light emission upon firing of the handgun. The dual mode pulse modulated laser may be programmed to operate in many ways. For example, (1) the laser may be switched “on” continuously until turned “off”; (2) the sighting laser may be programmed to pulse continuously; (3) the sighting laser may be on at all times while a pulse modulated laser signal is emitted only in response to a selected stimulus input; (4) the sighting laser may pulse with a pulse modulated laser emitting light only in response to a selected stimulus input; or (5) the sighting laser is off until triggered by a selected stimulus. Further, with a dual diode, the sighting laser may emit a visible wavelength light, while the pulse modulated diode emits an invisible or nearly invisible infrared wavelength signal, when stimulated.

In another embodiment each new magazine 34 that is inserted into the handgrip 55 of the handgun 10 may include a fresh battery (not shown) to power the laser circuitry within the casing 29 and energize the laser. This design concept alleviates the need to periodically disassemble the laser mechanism to replace battery 30.

The shooter may turn on the laser device by any of the switch means identified hereinabove. As the firing cycle begins, the driver board 27 is pre-programmed to emit the pulse modulated laser signal. If a target with an electronic sensor is used, the sensor can be programmed to detect a plurality of specific pulse modulated laser light emissions from a variety of handguns. The target impingement location of the pulse modulated laser emission provides information on the targeting skill and shooting accuracy of each individual shooter. This information can then be used to enable the shooter and/or the instructor to improve the targeting and shooting skills of the shooter.

As a training device, a light sensitive receptor on the target can be programmed to detect the specific coded pulse modulated light to indicate where the firearm was aimed and where actual projectile or electronic signal hit the target. The target may also be connected to a computer data collection system to determine how this particular shooter is performing. The laser light may be either visible or invisible to the human eye. When a visible laser light is used, it is not necessary that an electronically sensitive target be used. In military field training exercises, for example, “pop up” metallic targets are often used. Since pop up targets often have hundreds or thousands of marks on them from previous shooters, a modulated visible laser light would enable the instructor to determine that the target had been hit. In some circumstances it may be difficult of the operator of the firearm to see a modulated pulse of light, and therefore continuous light may also be used.

When multiple shooters are targeting the same object, a different color laser may be used for each different firearm, enabling the trainer to determine how each individual shooter is performing, and light receptors on the target system could be programmed to recognize the different colors. In situations where multiple shooters are firing at the same time, increased stress is imposed upon the shooters, thus enabling the instructor to determine the level of performance of each individual shooter under such critical situations. This would have application within both law enforcement and the military.

While this device has been described as a training tool, it has utility in real life, live fire situations. For example, in order not to give away a shooter's position, he or she might not want to turn on the constant laser until the last instant before firing. But, once turned on, the shooter will be able to determine where their bullet landed by seeing the continuous laser at the point of impingement. This would better protect the shooter from detection and provide the shooter with an element of surprise on their targeted victim.

Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention. 

1. A laser sighting device for a semi-automatic handgun having a recoil spring guide chamber housing a recoil spring surrounding a spring guide, the laser sighting device comprising: a pulse modulated laser received within the spring guide, having an input and a light output for emitting a pulse modulated laser light aligned with a path of a bullet fired by the handgun; and a sensor for detecting firing of the handgun, having an output coupled to the input of the pulse modulated laser; such that when the sensor detects the handgun has been fired, the output of the sensor triggers the pulse modulated laser to emit a train of pulses of laser light.
 2. The laser sighting device of claim 1 wherein the pulse modulated mode laser is selected from the group consisting of single mode laser and a dual mode laser.
 3. The laser sighting device of claim 1, wherein when the sensor detects the handgun has been fired the laser light emitted from the pulse modulated laser is modulated from a constant light to a brighter light intensity.
 4. The laser sighting device of claim 3, wherein the constant light is zero light intensity.
 5. The laser sighting device of claim 1 wherein the pulse modulated laser comprises: a driver board received by the spring guide coupled to a battery; a sensor coupled to the driver board; one or more laser diodes coupled to the driver board; a lens housing adjustable by at least one adjustment screw to align the pulse modulated laser; and a collimating lens received by the lens housing and coupled to the one or more laser diodes.
 6. The laser sighting device of claim 1 wherein the sensor is selected from the group consisting of a piezoelectric vibration sensor, a MEMS (micro electro mechanical system) accelerometer, a Hall effect magnetic sensor, a Reed effect magnetic sensor, a capacitive sensor, a carbon microphone, an acoustical sensor and an optical sensor.
 7. The laser sighting device of claim 1 wherein the pulse modulated mode laser emits a laser pulse with a light wavelength that is selected from the group consisting of visible, ultraviolet, near infrared and far infrared wavelengths.
 8. The laser sighting device of claim 1 wherein a duration of a pulse from the pulse modulated mode laser is between approximately 100 nanoseconds and approximately 200 microseconds.
 9. The laser sighting device of claim 1, wherein the pulse emitted from the pulse modulated mode laser is a pulse train comprising multiple independent individual laser pulses.
 10. The laser sighting device of claim 9, wherein each pulse train varies in duration from approximately 100 milliseconds to approximately 200 milliseconds.
 11. The laser sighting device of claim 1, wherein the sensor further detects a temporary disconnection between a battery within the spring guide and a contact pin of a posterior cap at an end of the spring guide. 